Re: Dump in-memory database to disk?

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Thomas Weholt wrote:
> Thanks for your reply :-)
> 
> I was hoping to avoid all the inserts and use some way of writing all
> the data directly to a database-file. I believe that would be faster,
> but perhaps it's not possible so I'll have to use the method you
> described.

I'm pretty sure the way I described is the only reasonable one. CREATE
TABLE AS SELECT is also as fast as you can normally get with a relational
database, aside from perhaps native dump/load calls, which SQLite does not
have.

> On a side note; are there any speed enhancements gained by using
> executemany vs. just execute?

There's only a single CREATE TABLE AS SELECT per table, and you can't use
executemany to replace the loop around that. executemany can only be used
for parametrized SQL statements. And you can only parametrize (with ?)
*values* in SQL, not *identifiers* like table or column names.

As a side-note, pysqlite 2.1.0 and later caches compiled statements anyway,
so execute() with parametrized statements is almost as fast as
executemany() nowadays.

- -- Gerhard
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